I remember my first Internet purchase, in 1986. Well, it was sort of an internet purchase, and I can't remember whether it was called the Internet then, or the Arpanet. There was a usenet group called forsale.something, and it had subgroups for different parts of the country. One day I saw an ad from someone nearby selling a used portable dishwasher. I made contact, and I think I went to his house to complete the purchase (Amazon didn't ship across the country back then, and you really didn't want to send your credit card number by email).
We used the dishwasher for several years, took it to Colombia with us, and eventually sold it down there for at least as much as we had paid + shipping.
Of course I was far from the only one to do this sort of thing--that's why forsale.whatever existed.